An air filter designed to remove particulate matter from an airstream generally is a device comprising fibrous materials. These fibrous materials may remove solid particulates such as dust, pollen, mold, and bacteria from the airstream. Air filters are used in applications where air quality is important, notably in building ventilation systems and with engines.
Air filters may be used in automobiles, trucks, tractors, locomotives and other vehicles that use internal combustion engines. Air filters may be used with gasoline engines, diesel engines, or other engines that utilize fossil fuels or other combustible substances. Air filters may be used with engines in which combustion is intermittent, such as four-stroke and two-stroke piston engines, as well as other types of engines that take in air continuously so that a combustible substance may be burned. For example, air filters may be used with some gas turbines. Filters may also be used with air compressors or in other devices that take in air.
Filters may be made from pleated paper, foam, cotton, spun fiberglass, or other known filter materials. Generally the air filters used with internal combustion engines and compressors tend to be comprised of either: paper, foam, or cotton filters. Some filters use an oil bath. Air filters for internal combustion engines prevent abrasive particulate matter from entering the engine's cylinders, where it would cause mechanical wear and oil contamination. In many fuel injected engines, a flat panel pleated paper filter element may be used. This filter is usually placed inside a plastic box connected to the throttle body with ductwork. Vehicles that use carburetors or throttle body fuel injection typically use a cylindrical air filter positioned above the carburetor or throttle body.
Air filters may also be used to filter cabin air, for example, air within a vehicle such as a car, truck, airplane, bus, train, tractor, etc. These air filters may typically be a pleated-paper filter in which outside-air is passed through the filters before entering the vehicle's passenger compartment. Some of these filters are rectangular and similar in shape to the combustion air filter.
While the present disclosure is subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. The invention should be understood to not be limited to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure.